From 9d79a3a99da734ac4f9dd748a05ff2c916926b46 Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Fri, 14 Aug 2020 19:12:10 +0300
Subject: [PATCH] lib/memory: add `-memory.allowedBytes` command-line flag for
setting absolute memory limit for VictoriaMetrics caches
---
lib/memory/memory.go | 31 +++++++++++++++++++++----------
1 file changed, 21 insertions(+), 10 deletions(-)
diff --git a/lib/memory/memory.go b/lib/memory/memory.go
index f9982098cf..d918caa0e0 100644
--- a/lib/memory/memory.go
+++ b/lib/memory/memory.go
@@ -8,9 +8,16 @@ import (
"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
)
-var allowedMemPercent = flag.Float64("memory.allowedPercent", 60, "Allowed percent of system memory VictoriaMetrics caches may occupy. "+
- "Too low value may increase cache miss rate, which usually results in higher CPU and disk IO usage. "+
- "Too high value may evict too much data from OS page cache, which will result in higher disk IO usage")
+var (
+ allowedPercent = flag.Float64("memory.allowedPercent", 60, "Allowed percent of system memory VictoriaMetrics caches may occupy. "+
+ "See also -memory.allowedBytes. "+
+ "Too low value may increase cache miss rate, which usually results in higher CPU and disk IO usage. "+
+ "Too high value may evict too much data from OS page cache, which will result in higher disk IO usage")
+ allowedBytes = flag.Int("memory.allowedBytes", 0, "Allowed size of system memory VictoriaMetrics caches may occupy. "+
+ "This option overrides -memory.allowedPercent if set to non-zero value. "+
+ "Too low value may increase cache miss rate, which usually results in higher CPU and disk IO usage. "+
+ "Too high value may evict too much data from OS page cache, which will result in higher disk IO usage")
+)
var (
allowedMemory int
@@ -24,15 +31,19 @@ func initOnce() {
// Do not use logger.Panicf here, since logger may be uninitialized yet.
panic(fmt.Errorf("BUG: memory.Allowed must be called only after flag.Parse call"))
}
- if *allowedMemPercent < 1 || *allowedMemPercent > 200 {
- logger.Panicf("FATAL: -memory.allowedPercent must be in the range [1...200]; got %f", *allowedMemPercent)
- }
- percent := *allowedMemPercent / 100
-
mem := sysTotalMemory()
- allowedMemory = int(float64(mem) * percent)
+ if *allowedBytes <= 0 {
+ if *allowedPercent < 1 || *allowedPercent > 200 {
+ logger.Panicf("FATAL: -memory.allowedPercent must be in the range [1...200]; got %f", *allowedPercent)
+ }
+ percent := *allowedPercent / 100
+ allowedMemory = int(float64(mem) * percent)
+ } else {
+ allowedMemory = *allowedBytes
+ }
remainingMemory = mem - allowedMemory
- logger.Infof("limiting caches to %d bytes, leaving %d bytes to the OS according to -memory.allowedPercent=%g", allowedMemory, remainingMemory, *allowedMemPercent)
+ logger.Infof("limiting caches to %d bytes, leaving %d bytes to the OS according to -memory.allowedPercent=%f and -memory.allowedBytes=%d",
+ allowedMemory, remainingMemory, *allowedPercent, *allowedBytes)
}
// Allowed returns the amount of system memory allowed to use by the app.